Relief valve



New, 4 1924.

J. N. GUNNING RELIEF VALVE File y 25. 1929 2 Sheets-sheaf l [Ni Elly TOR A TTOR/VEVS B Y WM A Nov. 4 1924.

J. N. GUNNING RELIEF VALVE Filed May 25, 1920 2 Sheets-Sheet 2 dlv Patented Nov. 4, 1924.

ED STATES JOHN NORMAN GUNNING. OF CHILLIC'OTHE, OHIO. I

RELIEF VALVE.

Application filed May 25, 1920. Serial No. 384,138.

To (ZZZ whom it may concern:

Be it known that I, JOHN NORMAN GUN- NING, a citizen of the United States of America, residing at Chillicothe, in the county of Ross and State of Ohio, have invented certain new and useful Improvements in Relief Valves, of which the following is a full, clear, and exact description.

In the operation of airbrake systems considerable difficulty has at times been encountered by reason of accumulation of water in the engines driving the air compressors by condensation of steam when the engines are not in operation, with resultant damage to the engines pistons or to the connections thereof with the piston rods, injury to the packing, and loss of lubricant. in cold weather the water may freeze, especially when the locomotive is idle during the night. Withthe object of mitigating these difficulties it has become the practice to provide the compressor en 'nes with hand-controlled drain or-relief va ves, which the engineman or attendant is supposed to open when the locomotive is laid up for the night or is to be out of use for any material period of time, so that the water may drain out as the steam is condensed, but this is sometimes forgotten. I have accordingly been led to devise my present invention, which has for its chief object to provide means which will automatically provide an outlet for water of condensation whenever the compressor engine is out of operation, Another object is to provide means whereby the steam passages of the compressor engine will have a small amount of steam flowing through them constantly when the engine is not in operation, so long as there is steam in the boiler, thereby keeping the'parts warm,

preventing freezing, and materially reduc ing if not eliminating condensation. To these and other ends the invention consists in the novel features of constructionand combinations of elements hereinafter described.

Of the various embodiments of which the invention is capable I have selected for illustration and specific description herein the one which at the present time is considered to exhibit the invention in its most convenient and effective form. This embodiment is shown in the accompanying drawings, in Which F'g. 1 illustrates the general air brake com ressor y t m havi g two Moreover,

shown, behind the cylinder.

lay-out of compressors and two engines. One of-the engines 1s shown in vertical section, somewhat diagrammatically.

Fig. 2 is a vertical section of the relief valve, showing the valve plunger in the pos1t1on which it normally occupies when the engine is not in operation.

Fig. 3 is a section similar to Fig. 2 but with the valve plunger in section, and showing the position of the valve plunger when steam at sufficient pressure is supplied to the engine to operate the latter.

Fig. 4 is a horizontal section on line 44 of Fig. 2.

Two compressors, 10, 11, and two engines therefore, 12, 13, are shown, engine 13 being in vertical section. The showing of the engines and compressors, especially engine 13, is somewhat diagrammatic in character, as the details of construction of these parts are largely immaterial and it is onl neces-.

and delivers exhaust steam from the underside of the engine piston 15, and passage 16 performs the same functions for the upperside. These passages, and exhaust passage 17 (connected behind the engine cylinder to the exhaust pipe 18), are controlled by the slide valve 19 working in the steam chest 20, to which live steam is supplied by branch pipe 21 through a suitable passage, not Engine 12,

which is like en ine 13, has a similar exhaust pipe 22, joining the other at 23, and a similar live steam pipe 2 1 and steam chest 25. The two live steam pipes 21 and 24 branch from a main supply pipe 26, which is controlled by an automatic throttle 27 and a hand throttle 28. The former will be recognized as a well known type, and its function is to cut off the supply of steam to the engines as soon as a predetermined air pressure is attained in the compressed air reservoirs, and to open and thereby to admit steam to the engines whenever the pressure falls to a predetermined int. It also opens whenever the hand t rottle 28 is As there shown it comprises an outer casing 30 and a closely fitting inner reciprooatory plunger 31 urged upwardly by a spring 32 seated in the lower portion of the casing. The latter has at its top a steam 1n.- let 33 for connection to the steam supply pipe 26, Fig. 1, by means of a small pipe 34 at a point between the two throttle valves 27, 28. At the bottom the casing 30 has a drain opening 35 for connection with one of the exhaust pipes, for example 22, by means of a small pipe 36. Above the spring 32 the casing has an inner tapered seat 37 for cooperation with a similarly tapered or conical valve 38 on the plunger 31, as clearly shown in Fig. 3. Below the valve 38 the plunger has a finned or ribbed pro ection 39, which rests on the spring and serves as a guide for the plunger in its vertical movements.

The cylindrical portion of the plunger 31 is formed at its top with one or more vertical passages 40 in the form of grooves communicating with two inwardly extending ports 41 which at their inner ends open into two downwardly extending passages 42, the latter being open at the bottom to the space above the cone-valve 38. The cap 43, which forms the upper portion or top of the easing 30, is of slightly greater internal diameter than the rest of the casing, thus providing an annular space to afford communication between ports 41 and the steam inlet opening 33 when the plunger is in its upper position. To keep the top of the plunger from seating against the top of the cap the former may be provided with one or more ribs, as 44.

Around the lower part of the cylindrical part 31 is a circumferential or annular groove 45,, communicating through one or more vertical grooves 46 with the space above the valve plug 38.

In a plane below the cylindrical plunger 31 when in its upper position, the casing.

30 is provided with one or more radial ports 50, four being shown, formed in radial arms 51, as indicated, for connection with the appropriate steam passages in the compressor engine or engines. In the present instance, two ports 50 which are diametrically opposite each other are connected by pipes 52, 53, to the respective passages 14 in the two engines 12, 13, and the other ports 50 are closed by suitable caps.

The o%eration will now be readily understood. eing on the live steam or boiler side of the automatic throttle 27 the closing of the latter does not affect the relief valve. Hence, whenever the hand throttle 28 is open, steam at the pressure supplied to theengines flows through pipe 34 and depresses the plunger 31, which seats the valve 38 and brings the groove 45 into registry with the ports 50, the latter being otherwise closed by the cylindrical plunger, as is clearly shown in Fig. 3. A small quantity of steam now flows down vertical grooves or passages 40, through lateral ports 41 and vertical ports 42 to the space between plunger 31 and valve 38, and thence up through groove 46 and around groove 45 to ports 50. On the up-stroke of the engine pistons the steam delivered to ports 50, as just described,-

passes into the passages 14 and enters the cylinders below the pistons, but on the downstroke the steam entering the passages 14 issues with the exhaust steam through the respective slide valves into the exhaust pipes 18 and 22.

Now when the hand throttle 28 is closed spring 32 raises the plunger 31 to the position shown in Fig. 2. The small amount of steam admitted to pipe 34 by the leakage port 28 -in the hand throttle 28 then passes through ports 41 and ports 42 to the chamber below the plunger 31, from whence at least part may flow down through outlet 35 and pipe 36 to exhaust pipe 22. At the same time, some of the live steam coming through port 28 passes into the branch pipes 21, 24 (the hand throttles 28" being open) and thence to the steam chests 20, 25. Now consider engine 13. If this stopped on the down-stroke (that is, with the slide-valve 19 at the left side of the steam chest 20,.Fig. 1) when the throttle 28 was closed, part of the steam delivered to the chamber below the plunger 31 (Fig. 2) from pipe 34 as described above will pass directly to the exhaust through outlet 35, and part may pass through pipe 52 to passage 14 and flow out to pipe 18 with the exhaust, while part of the steam from leakage port 28 passes by way of pipes 26 and 21 to the steam chest and thence through passage 16 (Fig. 1) to the upper side of the piston. After the piston settles this steam can escape through groove 54 (described below) and thence out through the relief valve outlet 35 to the exhaust pipe 22. On the other hand, if the engine sto ped with the piston 15 on the up-stroke the slidevalve being at the right as in Fig. 1), steam from pipe 21 will flow down passage 14 into pipe 52 and thence past the valve 38, Fig. 2, through pipe 36 to the exhaust pipe 22. The same is true of engine 12. Any water tending to collect in the bottom of the cylinders when the engines are not in operation finds ready escape through pipes 52 and 53 to port 35 and thence through pipe 36 to exhaust pipe 22. When the engines are stopped, on either the up or the down stroke, the pistons gradually settle, finally stopping a fraction of an inch lower than the lower limit of their travel when working. When the pistons are in the said lower or extreme non-working position, water which might otherwise collect above them drains out to of steam from one side of the pistons to the .other when the enginesare working.

From the foregoing it will be seen that there is a continual flow of live steam through the relief-valve passages and through the en ines, both when the engines are running an when they are not, thereby keeping the relief valve warm enough to prevent freezing and keeping the engines warm enough to prevent freezing u when they otherwise might by reason of tiie closing of the hand throttle, and in most cases warm enough to prevent condensation. At the same time the valve afl'ords free escape for any water that may happen to condense in the steam passages when the engines are not in operation.

' While the invention is 'designed particularly for airbrake engines, it can be used to advantage with other steam engines where similar protection is desired.

It is to be understood that the invention is not limited to the specific construction herein illustrated and described but can be ems bodied in other forms without departure from its spirit. I 3 o What I claim as my invention is:

1. The combination with the engine of an airbrake system, said engine having steam passages, and means for supplying steam to the engine to actuate the same, of a relief valve adapted to be closed by steam pressure supplied to the engine to actuate the latter, means operating when said steam pressure is shut olf to open the relief valve for escape of condensed steam from the engine, and means controlled by said valve for permitting live steam to How through at least one of said passages when the engine is idle.

2. The combination with the engine of an air-brake system, said engine having steam passages, and means for supplying steam to the engine to actuate the same, of a relief valve connected with said passages and with said steam-supplying means and adapted to be closed by steam pressure,-and' a spring arranged to open the valve when the steam pressure to the engine is shut ofi, said valve having passages cooperating with at least one of the said steam passages of the engine to permit flow of steam through the Same when the engine is idle.

3. The combination with the engine of an airbrake system, having steam passages, of a relief valve adapted to be closed by the steam pressure supplied to the engine when the latter is operating, automatic means to hold the valve open for escape of condensed steam from the engine when the latter is idle, and means for causing a continuous flow of live steam through the valve and through at least one of the said steam passages of the engine when the engine is idle.

4. The combination with the steam engine of an airbrake system, having steam passages; a'pipe for supplying live steam to the engine to actuate the same; a throttle in said pipe, having a leakage port; a relief valve connected with the pipe between the engine and the throttle and adapted to be closed by the steam pressure when the throttle is opened; and a spring to open the valve for the escape of water from the engine when the throttle is closed; said valve having passages for receiving steam from at least one of the said engine passages when the engine is idle and the valve open.

5. The combination with the engine of an airbrake system, having steam passages, of a relief valve adapted to be closed by the steam pressure supplied to the engine when the latter is, operating, automatic means to hold the valve open for escape of condensed steam from the engine when the latter is idle, and means for causing a continuous flow of live steam through the valve when the engine is idle and when operating, and through at least one of the said steam pas sages of the engine when the engine is idle.

6. The combination with the engine of an airbrake system,'having steam passages; of a pipe for supplying live steam to the engine; a throttle in said pipe,-having a leakage port to permit a small flow of steam past the throttle when the latter is closed; a valve connected with the said steam passages of the engine for escape of condensed steam therefrom when the engine is idle, said valve having passages for the flow of steam from at least one of the said engine passages when the engine is idle; and a pipe connecting the valve with said steam supply pipe between the throttle and the engine.

7. A relief valve for the purpose described, comprising a casing having an outlet provided with a valve seat, and having a port above said seat, a plunger movable in said casing and having a valve'to cooperate with said seat to close the outlet, :1 spring to raise the valve and plunger from said seat; passages in the plunger for the flow of steam to and from the said port; means for connecting the casing above the plunger to a source of steam; and means for connecting said port to a steam engine.

8. A relief valve for the purpose described, comprising a casing having an inlet and an outlet and having an intermediate port between the two, a plunger movable in I when the valve and plunger are lifted by the spring; I

9. A relief valve for the purpose described, comprising a casing having an inlet and an outlet and an intermediate port,-said outlet having a seat; a plunger movable in the casing; a valve carried by the plunger but spaced therefrom. to cooperate with said seat and thereby close said outlet, said plunger covering the intermediate port when the said valve is seated: and a spring to lift the valve and plunger; said plunger having passages for supplying steam to the intermediate port when the said outlet is lO. A relief valve for the purpose described, comprising a casing having an inlet and an outlet and an intermediate port, said outlet having a seat; a plunger movable in the casing, and adapted to close and open said intermediate port; a valve carried by the plunger but spaced therefrom, to cooperate with said seat when the said port is closed; and a spring to lift the valve and plunger; said plunger having longitudinal passages for supplying steam from the inlet end of the casing to said intermediate port when the said outlet is open.

11. A relief valve for the purpose described, comprising a casing having an inlet at one end, an outlet at the other end, and an intermediate port, said outlet having a seat; a plunger movable in the casing and having a valve spaced from the plunger to cooperate with said seat, and having internal passages for conveying steam from said inlet to the space between the plunger and the valve, said plunger being also provided with external passages for conveying steam from said space to the intermediate port when the outlet of the casing is closed by the said valve.

In testimony whereof I hereto aflix my signature.

JOHN NORMAN GUNNING. 

